The chicks are now as big as Promises and almost ready to leave the colony to begin life on their own. They have already left the nest and now they hang out with their friends in groups getting ready to head off out to sea. They only come looking for Promises when they want food.
I attach a photo showing how the chicks in the colony are now grouping together with their friends, slowly building up the courage to leave the colony. It is a scary moment for the youngsters. Life on their own out at sea is not easy.
They have never been to sea before, have never tried catching their own food, and have only their instincts to tell them where to go and how to get home.
A couple of the chicks in the photo have lost their chick feathers and are now ready to go to sea, whilst the others still need another week or so before they will be ready for the water.
At the moment the weather here is still nice. It has been a bit too hot for the penguins this year, and the warmer seawater has pushed fish stocks further away from the coast making it more difficult for Promises to bring back food for the chicks. However winter is not far away. This far south winter comes quickly.
The weather gets cold and the days get very short and gloomy, which is not good for catching fish underwater.
Last December it was bright and sunny from 4 o’clock in the morning until 10 o’clock at night, but it is very different now. The days are already getting a lot shorter. Penguins cannot catch fish if they can’t see them in the dark depths of the ocean, and the light quality drops quickly the deeper they dive.
So when the chicks leave the colony they will start travelling northwards towards the equator where there are longer hours of daylight during the winter.
The chicks have never been swimming before, and have very weak flipper muscles that have hardly been used yet. So the youngsters cannot swim very fast or very far, and are not fast enough to catch any fish. The fish are too fast for them, and it will take months of swimming before the youngsters develop flipper muscles strong enough to catch fish.
Thankfully the coastline has lots of kelp beds, which are underwater forests made up of very long brown seaweed. These kelp beds are common all around the world. You might have seen them yourself if you have spent any time near the sea. These kelp beds are like restaurants for the young penguins.
The brown ‘leaves” can be seen floating on the water surface, but those ‘leaves’
are just the tips of very long stems that go all the way down to the seabed where the plants are rooted. Pieces of the kelp often break off and wash up on the beach. They have little pods full of air which kids love to press and pop. Trees need strong trunks and branches to reach high enough to capture the sunlight, but under the water these pods of air are all that the kelp needs for its floppy stems to reach the sunlight.
These underwater forests are very important for the young penguins because they are home to shrimps and other small slow moving creatures which the slow swimming youngsters can easily catch and eat. They have been fed on top quality fish by Promises during the last few weeks, but now they will eat virtually any animal that is slow enough to catch, and small enough to swallow whole.
Penguins do not have teeth so they do not chew their food and have to swallow it whole. They do eat small stones which remain in the stomach and mash up the food during the digestive process. It is a bit like having teeth in their stomach instead of their mouth. That is why penguins can only eat things that are small enough to swallow whole. Having said that, it is amazing how big the fish are that Promises can swallow whole.
The reason that birds do not have teeth is that birds originally evolved to fly, and to fly it is important to be as light as possible. Teeth are not only quite heavy but they also require bone as a support for the teeth. The extra weight of jaw bones and teeth would make flying more difficult, so bird beaks are made from a much lighter material that is similar to your finger nails. You will know yourself how strong finger nails can be, and how light they are too.
Of course penguins can’t fly, but they are still birds, and therefore they still have the characteristics that they inherited from other birds, one of which is a beak instead of teeth.
Birds developed from small warm-blooded dinosaurs about 65 million years ago.
Warm-blooded means that they produce their own body warmth, enabling them to survive better in cold conditions. Birds developed feathers so as to keep that internal warmth from being lost, just like our clothes keep us warm, and around the same time warm-blooded mammals developed fur for the same reason.
Penguins branched off from other groups of birds about 45 million years ago.
The smallest known penguin was called Aprosdokitos mikrotero. It was only 35cm
(14″) tall, and lived on Earth around 34 million years ago. The largest penguin was called Palaeeudyptes idekowskii and it was a massive 220cm (7′ 4″) tall; much taller than any man. Good job they only ate fish.
Now that the chicks have left the nests and are grouped together ready for departure, it is difficult for us to know which chick is which, so we won’t know exactly which day your chicks head out to sea. Of course Promises will know, but won’t tell. We will find out though because when the chicks leave Promises will also leave the nest to go and have a long deserved rest out at sea.
Feeding the chicks has been very hard work for Promises, especially this year.
The adults have been getting up very early in the morning and working until late in the evening every single day for the last few weeks. Not only are they exhausted but they have also lost about a quarter of their body weight during the process.
So now that the chicks are leaving the colony, the first thing the adults have to do is spend a few weeks out at sea just relaxing and catching fish to get back into condition. At the moment they are too skinny and need to recover.
After a few weeks of eating and relaxing out at sea Promises will come back to the nest ready to change feathers. Penguins change their feathers every year to keep them in good condition. The chicks have only just changed their feathers ready for departure, but the adults have not changed theirs yet, and they have to do that too before they can begin following the chicks northwards.
I will write to you again in a few weeks as soon as we see Promises back home in the nest.
Best wishes, Mike